Shaped charge liner with multi-material particles

ABSTRACT

Embodiments relate to a liner for a shaped charge. The liner includes reactive particles, each having two reactive materials which together are capable of undergoing an exothermic and/or intermetallic reaction. Additionally, embodiments may include non-reactive particles, which typically have a higher density than the reactive particles. The reactive particles may be configured to produce an exothermic reaction upon detonation of the shaped charge. In some embodiments, one of the reactive materials may be coated onto a core of the other reactive material, to form the reactive particle. In other embodiments, each reactive particle may be formed as a conglomerate of the two reactive materials. Shaped charges having liners and methods of formation are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 63/322,926 filed Mar. 23, 2022, as well as U.S. Provisional Patent Application No. 63/231,016 filed Aug. 9, 2021, the entire contents of both of which are incorporated herein by reference.

BACKGROUND

As part of a well completion process, cased-holes/wellbores are perforated to allow fluid or gas from rock formations (reservoir zones) to flow into the wellbore. Perforating gun string assemblies are conveyed into vertical, deviated or horizontal wellbores, which may include cemented-in casing pipes and other tubulars, by slickline, wireline or tubing conveyance perforating (TCP) mechanisms, and the perforating guns are fired to create openings/perforations in the casings and/or liners, as well as in surrounding formation zones. Such formation zones may include subterranean oil and gas shale formations, sandstone formations, and/or carbonate formations.

Shaped charges are used typically to form the perforations within the wellbore. These shaped charges, serve to focus ballistic energy onto a target, thereby producing a round perforation hole (in the case of conical shaped charges) or a slot-shaped/linear perforation (in the case of slot shaped charges) in, for example, a steel casing pipe or tubing, a cement sheath and/or a surrounding geological formation. In order to make these perforations, shaped charges typically include an explosive/energetic material positioned in a cavity of a housing (i.e. a shaped charge case), with or without a liner positioned therein. It should be recognized that the case or housing of the shaped charge is distinguished from the casing of the wellbore, which is placed in the wellbore after the drilling process and may be cemented in place in order to stabilize the borehole prior to perforating the surrounding formations. Often, the explosive materials positioned in the cavity of the shaped charge case are selected so that they have a high detonation velocity and pressure. When the shaped charges are initiated, the explosive material detonates and creates a detonation wave, which will generally cause the liner (when used) to collapse and be ejected/expelled from the shaped charge, thereby producing a forward moving perforating material jet that moves at a high velocity. The perforating jet travels through an open end of the shaped charge case which houses the explosive charge, and serves to pierce the perforating gun body, casing pipe or tubular and surrounding cement layer, and forms a cylindrical/conical tunnel in the surrounding target geological formation.

Typically, liners include various powdered metallic and non-metallic materials and/or powdered metal alloys, and binders, selected to generate a high-energy output or jet velocity upon detonation and create enlarged hole (commonly referred to as “big hole”) or deep penetration (“DP”) perforations. These liners, however, may leave undesirable slugs/residuals of the liner material in the perforation tunnel, which may reduce and/or block flow of the fluid/gas in the perforation tunnel. Additionally, the perforating jet formed by typical liners may form a crushed zone (i.e., perforation skin, or layer of crushed rock between the round perforation/slot-shaped perforation tunnel and the reservoirs) in the surrounding formation, which reduces the permeability of the surrounding formation and, in turn, limits the eventual flow of oil/gas from the reservoir.

Efforts to reduce slug formation, further clear the perforation tunnel, and/or remove the crushed zone have included the use of reactive liners. Such reactive liners are typically made of a plurality of reactive metals that create an exothermic reaction upon detonation of the shaped charge in which they are utilized. Powdered metallic materials often used by the reactive liners include one or more of lead, copper, aluminum, nickel, tungsten, bronze and alloys thereof. Some of these powdered metallic materials may be heterogeneous or non-uniformly distributed in the liner, which may lead to reduced performance and/or non-geometric perforation holes. Also, the presence of non-reactive material in between reactive material may interfere with the completeness of the reaction of the reactive materials. Another common disadvantage of these liners is that they may not be able to sufficiently reduce slug formation, clear the perforation tunnel, and/or remove the crush zone formed following detonation of the shaped charge.

In view of the disadvantages associated with currently available methods and devices for perforating wellbores using shaped charges, there may be a need for a device and method that provides a composition including metal powders for use in a shaped charge liner that is capable of generating an energy sufficient to initiate an exothermic reaction upon detonation of the shaped charge. Additionally, there may be a need for shaped charge liners capable of forming an exothermic reaction to generate a thermal energy that creates a uniform perforating jet. There may be a need for a shaped charge liner in which its components allow for a more effective perforating jet, without adding significantly to overall shaped charge costs. For example, there may be a need for a liner configured to maximize the interaction of the reactive materials, which may thereby maximize the resulting exothermic reaction when the shaped charge is detonated. There may be a need for a cost-effective way to improve liner performance, for example manufacturing liners with improved performance without significantly increasing costs. Disclosed embodiments may provide one or more of these benefits.

BRIEF DESCRIPTION

According to an aspect, embodiments relate to a liner for a shaped charge. The liner includes reactive particles, each having at least two reactive materials which together are capable of undergoing an exothermic reaction. Additionally, embodiments may include non-reactive particles, which typically have a higher density than the reactive particles. The reactive particles may be configured to produce an exothermic reaction upon detonation of the shaped charge. In some embodiments, the exothermic reaction may be an intermetallic reaction. In some embodiments, one of the reactive materials may be coated onto a core of the other reactive material, to form the reactive particle. In other embodiments, each reactive particle may be formed as a conglomerate of the two reactive materials.

According to another aspect, an exemplary liner for a shaped charge may include a plurality of non-reactive particles and a plurality of reactive particles. The reactive particles may be configured to produce an exothermic reaction upon detonation of the shaped charge. For example, the reactive particles may each include two reactive materials, which together are capable of undergoing an exothermic reaction. In some embodiments, the reactive particles may not include substantially any non-reactive material. In some embodiments, the reactive particles may be substantially free of non-reactive material and/or may consist essentially of the two reactive materials.

According to yet another aspect, an exemplary liner for a shaped charge may include a plurality of non-reactive particles and a plurality of reactive particles, with each reactive particle configured to produce an exothermic intermetallic reaction upon detonation of the shaped charge. According to an aspect, the reactive particles each comprise aluminum and nickel, and each of the reactive particles may include a conglomerate of the aluminum and nickel, or a core of a first one of the aluminum and nickel, which is coated with a second one of the aluminum and nickel. For example, the reactive particles may each include a core of aluminum coated with a coating of nickel.

According to another aspect, embodiments may relate to a shaped charge. The shaped charge may include a case having a cavity, an explosive load disposed within the cavity of the case, and a liner disposed adjacent (e.g. over) the explosive load and configured for retaining the explosive load within the cavity of the case (e.g. with the explosive load disposed between the shaped charge case and the liner). In some embodiments, the liner may include reactive particles, each having two reactive materials which together are capable of undergoing an intermetallic reaction. Additionally, embodiments may include non-reactive particles, which typically have a higher density than the reactive particles.

According to yet another aspect, methods of forming a liner for a shaped charge are disclosed. Exemplary method embodiments may include the steps of forming or providing reactive particles (for example, each having two reactive materials); forming or providing non-reactive particles (for example, each having non-reactive material); mixing/blending the reactive and non-reactive particles to form a liner powder; and forming the liner powder into a desired liner shape. For example, forming the liner powder into a desired liner shape may include the steps of compressing and shaping the liner powder into the liner configured to fit within the shaped charge case. In some embodiments, the two reactive materials together may be capable of an exothermic reaction. According to an aspect, the two reactive materials together may be capable of an intermetallic reaction. In some embodiments, the reactive particles may be substantially free of non-reactive material.

BRIEF DESCRIPTION OF THE FIGURES

A more particular description will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments thereof and are not therefore to be considered to be limiting of its scope, exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1A is a cross-sectional view of a conical shaped charge liner having a composition of metal powders, according to an embodiment;

FIG. 1B is a cross-sectional view of a hemispherical shaped charge liner having a composition of metal powders, according to an embodiment;

FIG. 1C is a cross-sectional view of a trumpet shaped charge liner having a composition of metal powders, according to an embodiment;

FIG. 2 is a cross-sectional view of a slot shaped charge having a shaped charge liner, according to an embodiment;

FIG. 3 is a perspective view of a conical shaped charge having a shaped charge liner, according to an embodiment;

FIG. 4 is a schematic view illustrating the composition of an exemplary liner, according to an embodiment;

FIG. 5 , is a schematic view illustrating the composition of another exemplary liner, according to an embodiment;

FIG. 6A is a cross-section view of an exemplary reactive particle, according to an embodiment;

FIG. 6B is a cross-section view of another exemplary reactive particle, according to an embodiment;

FIG. 6C is a schematic cross-section view of yet another exemplary reactive particle, according to an embodiment; and

FIG. 7 is perspective cut-away view (e.g. partial cross-section) of still another exemplary reactive particle, according to an embodiment.

Various features, aspects, and advantages of the embodiments will become more apparent from the following detailed description, along with the accompanying figures in which like numerals represent similar components throughout the figures and text. The various described features are not necessarily drawn to scale, but are drawn to emphasize specific features relevant to some embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments. Each example is provided by way of explanation, and is not meant as a limitation and does not constitute a definition of all possible embodiments.

For purposes of illustrating features of the embodiments, embodiments will now be introduced and referenced throughout the disclosure. Those skilled in the art will recognize that these examples are illustrative and not limiting and are provided purely for explanatory purposes.

In the illustrative examples and as seen in FIGS. 1-3 a liner 10 for use in a shaped charge 20, 30 is illustrated. As illustrated in FIGS. 2-3 , the shaped charge 20, 30 may include a case/shell 40 having a plurality of walls 42. The plurality of walls may include a side wall 44 and a back wall 46′, 46″, that together define a hollow interior/cavity 50 within the case 40. The case 40 includes an inner surface 47 and an outer surface 48. An explosive load 60 may be positioned within the hollow interior 50 of the case 40, along at least a portion of the inner surface 47 of the shaped charge case 40. According to an aspect, the liner 10 is disposed adjacent the explosive load 60, so that the explosive load 60 is disposed adjacent the side walls 44 and the back walls 46′, 46″ of the case 40. The shaped charges 20, 30 have an open end 22, through which a jet is eventually directed, and a back end (closed end) 24, which is typically in communication with a detonating cord 70.

The illustrative liners 10A/10B/10C, as seen for instance in FIGS. 1A-1C, may be formed of a single layer (as shown). In an alternative embodiment, the liner 10A/10B/10C may also include multiple layers (not shown). An example of a multiple-layered liner is disclosed in U.S. Pat. No. 8,156,871, hereby incorporated by reference to the extent that it is consistent and compatible with the disclosure. In an embodiment, the shaped charge liner 10A/10B/10C has a thickness T ranging from between about 0.5 mm to about 5.0 mm, as measured along its length L. The thickness T is, in one embodiment, uniform along the liner length L, but in an alternative embodiment, the thickness T varies in thickness along the liner length L, such as by being thicker closer to the walls of the case 40 and thinner closer to the center of the shaped charge 20, 30 (or apex 18 of the liner). Further, in one embodiment, the liner 10A may extend across the full diameter of the cavity 50 as shown. In an alternative embodiment, the liner 10A/10B/10C may extend only partially across the diameter of the cavity 50, such that it does not completely cover the explosive load 60 (not shown). The liner 10A/10B/10C may be present in a variety of shapes, including conical shaped as shown in FIG. 1A, hemispherical or bowl-shaped as shown in FIG. 1B, or trumpet shaped as shown in FIG. 1C. The conical, hemispherical and trumpet liners 10A, 10B, 10C, respectively, may collectively be referred to as a liner/(s) 10. In some embodiments, the composition of the liner 10 may be substantially uniform when measured at any position along the length of the liner 10. For instance, a measurement of the constituents of the liner 10 taken at a first end 14 of the liner 10 may be identical to another measurement of the constituents of the liner 10 taken at a second end 16 or an apex (i.e., a midpoint between the first and second ends 14, 16) 18 of the liner 10.

In some embodiments, the liner 10 includes a plurality of non-reactive particles, and a plurality of reactive particles configured to produce an exothermic reaction upon detonation of the shaped charge. For example, FIGS. 4 and 5 illustrate exemplary mixtures of reactive particles 404 and non-reactive particles 406 forming the liner 10. In FIG. 4 , the blend/mixture of liner powder may include a substantially homogeneous mix of reactive particles 404 and non-reactive particles 406. In FIG. 5 , the blend/mixture of the liner powder may include a substantially homogeneous mixture of reactive particles 404, non-reactive particles 406, and binder material 502.

As used herein, the term “reactive” used with reference to a particle or material may refer to a particle or material relating to a primary (for example, most energetic) exothermic and/or intermetallic reaction in the liner. For example, the reactive materials may be the reactants in the primary reaction, and the reactive particles may each be formed of the reactive materials (for example, including the reactants for the primary reaction). Reactive materials may be capable of an intermetallic and/or exothermic rection with other reactive materials (reactants) in the reactive particle and/or liner 10 (e.g. as reactive pairs). Reactive particles may comprise or consist essentially of reactant pairs of reactive material which are capable of undergoing the primary reaction upon explosion of the shaped charge. For example, explosion of the shaped charge may be sufficient to initiate the primary reaction of the reactive materials in a reactive particle, thereby generating at least 180, at least 240, or at least 300 cal/g of heat/energy (for example 180-1400 cal/g, 180-750 cal/g, 180-330 cal/g, 240-1350 cal/g, 240-750 cal/g, 240-350 cal/g, 300-1320 cal/g, 300-750 cal/g, or 300-350 cal/g). Example reactive material pairs may include aluminum and nickel, aluminum and titanium, and titanium and carbon (e.g. graphite).

On the other hand, the term “non-reactive” used with reference to a particle or material may be considered in comparison to the term “reactive,” for example with non-reactive materials not undergoing the primary reaction with one or both of the reactive materials of the liner. For example, the term “non-reactive” used with reference to a particle or material may refer to a particle/material that is entirely or substantially non-reactive (e.g. not capable of undergoing an intermetallic reaction and/or producing an exothermic reaction, for example with other materials in the liner 10), or a particle/material that is less (e.g. typically substantially less) reactive in comparison to the reactive particle or materials. For example, any (secondary) reaction between non-reactive material and one or both of the reactive materials would be less energetic than the primary reaction, for instance with any such secondary reaction producing no more than 150 cal/g (e.g. 0-150 cal/g), no more than 120 cal/g (e.g. 0-120 cal/g), or no more than 110 cal/g (e.g. 0-110 cal/g).

Most typically, the reactive particles may each include two reactive materials (e.g. a reactant pair) which react together in an exothermic and/or intermetallic reaction (i.e. the primary reaction), and the non-reactive particles may include non-reactive material. In some embodiments, the non-reactive material may not react with one or both of the reactive materials of the reactive particles in a primary exothermic or intermetallic reaction (e.g. any reaction between the non-reactive material and one of the reactive materials would be a less energetic secondary reaction). So for example, the shaped charge liner 10 typically includes a combination of reactive particles 404 (e.g. powder grains) and non-reactive particles 406 (e.g. powder grains). In some embodiment, the non-reactive material may be dense (e.g. with a density greater than 8.5 g/cm³ (such as approximately 8.5 to 20 g/cm³), greater than 15 g/cm³ (e.g. 15 to 20 g/cm³), or greater than 19 g/cm³ (e.g. 19-20 g/cm³)), and may be termed dense non-reactive material (such as tungsten and/or bronze, for example).

Upon detonation of the shaped charge, the reactive particles 404 may produce an exothermic reaction, which may heat any material in the perforation channel and lead to a pressure pulse which travels through the perforation tunnel leading to removal of the crushed zone. The exothermic reaction of the liner 10 may be capable of reducing the impairment on the perforation tunnel inner wall or skin effect, leading to better flow through the perforation. Tests with the liner 10 (e.g. having reactive and non-reactive particles (404 and 406), as described herein) have shown that this effect is significant, for example providing over 20% more productivity (flow), on average, and up to 50% higher compared to previous state of the art reactive charges.

In some embodiments (for example, as shown in FIGS. 4-5 ), the liner 10 may be formed of a liner powder or composition 12 having the reactive particles 404 and the non-reactive particles 406. In some embodiments, the non-reactive particles 406 may be dense non-reactive particles, which may for example provide more penetration. In some embodiments, the reactive particles 404 may form approximately 10-30% by weight of the liner 10. In some embodiments, the non-reactive particles 406 may form approximately 39-80% by weight of the liner 10. In some embodiments, the reactive particles 404 may form approximately 15-25% by weight of the liner 10. In some embodiments, the non-reactive particles 406 may form approximately 60-80% by weight of the liner 10. In some embodiments, the non-reactive particles 406 may form approximately 39-60% by weight of the liner 10. In some embodiments, the non-reactive particles 406 may be dense non-reactive particles and may form approximately 60% by weight of the liner 10. In some embodiments, the non-reactive particles may be dense non-reactive particles and may form approximately 80% by weight of the liner. In some embodiments, the reactive particles 404 may form approximately 20-25% by weight of the liner 10. In some embodiments, the reactive particles 404 may form approximately 38-41% by volume of the liner 10. In some embodiments, the non-reactive particles 406 may form approximately 38-60% by volume of the liner 10. In some embodiments (for example, as shown in FIG. 5 ), the binder material 502 may form approximately 22% by volume of the liner 10. In some embodiments, the binder material 502 may form at least approximately 15% by weight of the liner 10 (for example, 15-22% by weight). In some embodiments, the binder material 502 may form approximately 20-22% by weight of the liner 10.

The reactive particles 404 may each include two (e.g. typically only two, or in some embodiments, more than two) reactive materials which together are capable of undergoing an exothermic and/or intermetallic reaction (e.g. a primary reaction). According to an aspect, the reactive materials may include a metal and a non-metal. In other aspects, the reactive materials may include two metals. In some embodiments, the two reactive materials may be present in each reactive particle in proportions corresponding to the formula for the exothermic and/or intermetallic reaction using those two reactive materials. In some embodiments, the reactive particles 404 may not include any (or substantially any) non-reactive material (for example, the reactive particles 404 may each be substantially free of non-reactive material). The presence of any substantial amount of non-reactive material may inhibit the intermetallic reaction, for example by blocking intimate contact between portions of the two reactive materials, which may reduce the effectiveness of the liner 10. In some embodiments, the non-reactive material in a reactive particle may be less than 25% or no more than 22% by weight (for example, 0 to 25% or 0 to 22%). In some embodiments, the reactive particles 404 may include only reactive materials. In some embodiments, substantially all of the reactive material in the liner 10 may be disposed in the reactive particles 404. Typically, the reactive particles 404 are less dense than the non-reactive particles 406. In some embodiments, the non-reactive material is denser (for example, significantly denser) than the reactive materials. In some embodiments, the density of the non-reactive material may be at least twice or at least three times the density of the reactive particles 404. For example, the non-reactive material may have a density of at least about 8.79 g/cm³, about 8.79-19.3 g/cm³, about 16-20 g/cm³, about 19.3 g/cm³, or at least 19 g/cm³. The reactive material, on the other hand, may have a density of about 5-7 g/cm³, in some embodiments.

In some embodiments, the two reactive materials may be reactants for the intermetallic reaction. In some examples, the two reactive materials may include a metal and a non-metal which together are capable of undergoing an exothermic reaction. In other examples, the two reactive materials may include two metals which together are capable of undergoing an intermetallic reaction. For example, the two metals (e.g. reactive materials) may include aluminum and nickel. In some embodiments, each reactive particles 404 may include approximately 5-25% aluminum by weight, with the remainder being nickel. In some embodiments, the reactive particles 404 may each include approximately 80% nickel and 20% aluminum by weight. In some embodiments, the nickel may form a coating that encloses or encapsulates the aluminum sufficiently to prevent oxidation of the aluminum. For example, a core of aluminum may have a diameter of approximately 10-300 μm (e.g. approximately 50-100 μm in some embodiments), and the nickel coating may have a thickness of approximately 10-20 μm. In other embodiments, the two reactive materials (e.g. reactive pairs for each reactive particle) may include aluminum and nickel, aluminum and titanium, titanium and carbon, or carbon and aluminum. Some embodiments may further include chromium (for example, as an inert material, as discussed below). According to an aspect, a nickel-aluminum-chromium alloy is included for use in reactive particles. The nickel-aluminum-chromium alloy may have a service temperature of up to about 1000° C. (1830° F.). By way of specific example, the reactive particles 404 may include Oerlikon Metco 404NS or 1101 or Amdry 510, for example as produced by Oerlikon Metco.

In some embodiments, the reactive particles may further include one or more inert material. The term “inert” with reference to material herein may refer to material that is non-reactive or substantially inert with respect to the reactive materials of the liner, but which may be capable of creating an exothermic and/or intermetallic reaction with certain rock formations (e.g. with components of certain rock formations, such as silicon). In some embodiments, inert material may be less dense (e.g. with a density less than 8.5 g/cm³) than the dense non-reactive material. In some embodiments, the inert material of the reactive particles 404 may be configured so as to not substantially reduce exothermic and/or intermetallic reaction between the reactive materials of the reactive particles 404. In some embodiments, the inert material in a reactive particle 404 may be less than 25% (e.g. 0-25%) or no more than 22% (e.g. 0-22%) by weight. In some embodiments, the inert material in a reactive particle 404 may be approximately 22-25% by weight. In some embodiments, the inert material may be effectively distributed in the reactive particles 404 to prevent clumping and/or to allow for intimate contact between the two reactive materials. In some embodiments, the inert material may be capable of creating an exothermic and/or intermetallic reaction with certain rock formations (e.g. with components of certain rock formations). By way of example, in some embodiments the reactive particles 404 may comprise chromium (as an inert material), which may for example react with silicon in the rock formation. For example, in some embodiments the reactive particles may comprise aluminum, nickel, and chromium. The aluminum and nickel may be reactive materials which undergo intermetallic reaction, while the chromium may be an inert material that does not react with the aluminum or nickel, but which may react with silicon in the rock formation. In some embodiments, the reactive particles 404 may each have approximately 22% chromium by weight, approximately 10% aluminum by weight, and approximately 66-68% nickel by weight. In some embodiments, the inert material may be included in the liner powder, but may not be disposed in the reactive particles 404. For example, non-reactive particles 406 may include inert material and/or inert material may be included in the liner 10 as separate inert particles (not shown).

In some embodiments, the reactive particles 404 may each include a conglomerate of the two reactive materials (for example, a first reactive material 605 and a second reactive material 610, which may be joined in a composite mass). For example, in some embodiments, each conglomerate reactive particle 404 is formed so that each of the two reactive materials are concentrated at distinct portions of the conglomerate reactive particle (for example, adjacent each other). In some conglomerate embodiments, the two reactive materials may be delineated and/or formed with distinct layers. In some conglomerate embodiments, the two reactive materials may be formed into reactive particles 404 without admixing (for example, the two reactive materials may be segregated and/or not intimately blended—non-homogeneous). In some embodiments, the two reactive materials may be located on opposite sides of the reactive particle, as illustrated in FIG. 6A for example. For example, there may be a first distinct region of each reactive particle 404 having the first reactive material 605, and a second distinct region having the second reactive material 610. In some embodiments, the first distinct region may be opposite the second distinct region in the reactive particle. In some embodiments, all of the first reactive material 605 may be disposed in the first region, while all of the second reactive material may be disposed in the second region. In some embodiments, the two reactive materials may be disposed in a plurality of distinct layers or segregations (e.g. clumps), as illustrated in FIG. 6B for example. For example, the first reactive material 605 may be disposed in a plurality of first regions, the second reactive material 610 may be disposed in one or more second regions, and the first regions and second regions may be distributed or spaced throughout each reactive particle 404. In other embodiments, however, each of the conglomerate particles may have the two reactive materials distributed throughout (for example, intimately mixed). For example, the two reactive materials 605, 610 may be substantially homogeneously distributed throughout each reactive particle 404, as illustrated in FIG. 6C for example. In some conglomerate embodiments, the reactive materials are not coated (for example, not formed with one reactive material coated onto a core or another coating of another reactive material).

In other embodiments, for example as shown in FIG. 7 , the reactive particles 404 may each include a core 705 of a first reactive material 605 of the two reactive materials, which is coated with a coating 710 of a second reactive material 610 of the two reactive materials. For example, a core of aluminum may be coated with a coating of nickel in some embodiments. In some embodiments, the coating material may be selected to be the reactive material that is less likely to oxidize (of the two reactive materials forming the reactive particle 404).

In some embodiments, the reactive particles 404 may be substantially free of non-reactive materials. For example, the reactive particles 404 may have no more than 0.1% non-reactive materials by weight. In some embodiments, the reactive particles 404 may each consist essentially of the two reactive materials 605, 610. In some embodiments, different reactive particles 404 may include different pairs of reactive materials (for example, with each reactive particle 404 including a reactive pair of materials, but with some reactive particles 404 having different reactive pairs). In some embodiments, all of the reactive particles 404 may include the same reactive material pair. In some embodiments, the reactive particles 404 may not include a core of non-reactive material. In some embodiments, the reactive particles 404 may each be spheroidal or rounded, for example as shown in FIG. 7 . In some embodiments, at least some reactive particles 404 may include a conglomerate of the two reactive materials. In some embodiments, at least some of the reactive particles 404 may include a core of a first reactive material 605, which is coated with the second reactive material 610. In some embodiments, the reactive particles 404 may include conglomerate reactive particles and/or coated reactive particles (e.g. with a core of the first reactive material 605 coated with a coating of the second reactive material 610), for example with each reactive particle 404 being one or the other.

In some embodiments, the reactive particles 404 may have a diameter of about 20-300 micrometers. In some embodiments, the reactive particles 404 may have a diameter of about 50-90 micrometers. In some embodiments, each reactive particle 404 may be a grain of reactive powder. In some embodiments, each non-reactive particle may be a grain of non-reactive powder. The powders may be formed by any powder production techniques, such as, for example, any one or more of grinding, crushing, gas atomization, and various chemical reactions. In some embodiments, the reactive particles 404 and the non-reactive particles 406 may be mixed (for example, substantially homogeneously) and compressed to form the liner 10.

In some embodiments, the non-reactive particles 406 may include non-reactive material (e.g. dense non-reactive material). In some embodiments, the non-reactive particles 406 may not include substantially any reactive material (e.g. approximately zero). For example, the non-reactive particles 406 may substantially include only one or more non-reactive material (e.g. consist essentially of non-reactive material). In some embodiments, each non-reactive particle 406 may consist essentially of a single non-reactive material. For example, in some embodiments each non-reactive particle 406 may include one of the following: tungsten, bronze, and copper. In some embodiments, different non-reactive particles 406 may include different non-reactive materials. For example, in some embodiments the non-reactive particles 406 may include some combination of two or more of the following: tungsten particles, bronze particles, and copper particles. In some embodiments, substantially all of the non-reactive material of the liner 10 may be disposed in the non-reactive particles 406. In some embodiments, the non-reactive particles 406 may include tungsten, copper, bronze, or combinations thereof (for example, each non-reactive particle consisting essentially of tungsten, copper, bronze, and combinations thereof). In some embodiments, the non-reactive particles 406 may include a high-density material, such as a high-density metal. In some embodiments, the density of the non-reactive material may be at least twice or at least three times the density of the reactive particles. For example, the non-reactive material may have a density of at least about 8.79 g/cm³, about 8.79 to 19.3 g/cm³, about 16 to 20 g/cm³, about 19.3 g/cm³, or at least 19 g/cm³. In some embodiments, the non-reactive particles 406 may have a larger average diameter than the reactive particles 404. In some embodiments, the non-reactive particles 406 may have a diameter of approximately 50-200 micrometers, approximately 50-100 micrometers, or approximately 100-200 micrometers.

In some embodiments, the liner 10 may be substantially entirely formed of reactive particles 404 and non-reactive particles 406, for example as shown in FIG. 4 . In some embodiments, the reactive particles 404 and non-reactive particles 406 may be mixed with a binder material 502. In some embodiments, the liner 10 may be substantially entirely formed of reactive particles 404, non-reactive particles 406, and binder material 502, for example as shown in FIG. 5 . The mixture of reactive particles 404, non-reactive particles 406, and/or binder material 502 may form a liner powder blend (for example, composition) from which the liner 10 may be formed. A liner 10 having a homogenous liner powder blend may include a powder distribution variance, e.g., a standard deviation in the grain size distribution, for example of 1 to 5%. A liner 10 having a homogenous liner powder blend may include an even distribution of grain size ranges and types of powders throughout both the width and the length of the liner. In some embodiments, the liner 10 may be configured to fit within a shaped charge case 40. The liners 10 of the shaped charges 20, 30 may be formed to a desired shape prior to being placed/installed within the shaped charges 20, 30. In an embodiment, the liners 10 are pre-pressed to their desired shape, and are thereafter installed in the shaped charge 20, 30 by being machine or manually placed onto the explosive load 60.

In some embodiments, the reactive materials may include one or more of an aluminum metal powder, a nickel metal powder, a titanium metal powder, and a graphite metal powder. For example, the reactive materials may include a nickel-aluminum conglomerate or a nickel-aluminum-chromium conglomerate. One or more of the powders may exothermically react with another of the powders (e.g. forming a pair of reactive materials). The reaction may occur at a relatively low temperature, and may help to produce additional energy, that is, energy that is not formed by the activation of explosive loads 60 of a shaped charge 20, 30 as described in more detail hereinbelow. The additional energy produced by the composition of the liner powder may raise the total energy of the shaped charge liner 10 to a temperature level that helps facilitate a second reaction within the perforation tunnel. This second reaction may be an exothermic reaction and/or an intermetallic reaction that produces less, the same, or more energy than the initial explosion that forms the perforating jet. In other words, the second reaction may require a higher ignition temperature, but the end result may be a more consistent collapse of the liner 10, which leads to more reliability of the performance of the shaped charges 20, 30. For instance, for reactive materials/reactive particles including titanium and aluminum (i.e., Ti—Al), or alternatively titanium and carbon (i.e. Ti—C), the reactions that occur are represented by the following chemical formulas:

Ti+2Al=TiAl₂  (Formula 1)

Ti+C=TiC  (Formula 2)

where, Ti represent titanium, Al represents Aluminum, and C represents Carbon. In the reaction according to Formula 1, the ignition temperature is 400° C. and the heat generated by the reaction is 520 cal/g. In the reaction according to Formula 2, however, the ignition temperature is about 600° C. and the heat generated is about 860 cal/g.

In some embodiments, the shaped charge liner 10 may further include a binder 502 and/or a lubricant that aids with enhancing the producibility and the homogeneity of the composition 12 of the liner 10. According to an aspect, the binder 502 and lubricant may serve as a carrier agent that helps facilitate the homogeneity of the composition. The binder 502 may include a polymer resin or powder, or wax or graphite. According to an aspect, the binder 502 can also be an oil-based material. Other binders 502 may include soft metals such as lead, tin, or copper. In some embodiments, binder materials may be non-reactive material. In some embodiments, the binder may not be dense non-reactive materials (e.g. the non-reactive material in non-reactive particles typically may be denser than the binder material). In some embodiments, the non-reactive material of the non-reactive particles may serve as the binder (e.g. without any other, separate binder material being required for the liner). For example, some liner embodiments may only include reactive particles and dense non-reactive particles. The lubricant may help to bind one or more of the powders in the composition having low grain size ranges, such as, for example graphite powder, so that during the mixing process, the risk of loss of powders due to their fineness or low granularity and/or potential contamination of the work environment is reduced. According to an aspect, the graphite powder may function as the lubricant. In an embodiment, the shaped charge liner 10 additionally includes an oil, which may function as the lubricant, and prevent oxidation of the liner 10. The oil may be uniformly intermixed with each of the metal powders and the graphite powder. The oil may also enhance the homogeneity of the powders along the length L (and across the thickness T) of the liner 10. The oil, even when present in trace amounts, aids with thorough blending/mixing of the powders (having various grain size ranges) of the composition 12. In some embodiments, each of the liner powder, the binder and the lubricant will be uniformly interspersed throughout the liner 10, so that the liner 10 will have the same properties along any portion of its length L.

In some embodiments, the liner powder may include approximately 55-65% tungsten non-reactive particles by weight, approximately 15-25% bronze or copper non-reactive particles by weight, and approximately 10-30% reactive particles by weight. For example, the liner powder may include approximately 60% tungsten non-reactive particles by weight, approximately 20% bronze or copper non-reactive particles by weight, and approximately 20% reactive particles by weight. In some embodiments, the liner powder may include approximately 50-70% tungsten non-reactive particles by weight, approximately 15-25% binder particles by weight, and approximately 10-30% reactive particles by weight. For example, the liner powder may include approximately 60% tungsten non-reactive particles by weight, approximately 20% binder (such as lead) particles by weight, and approximately 20% reactive particles by weight. In some embodiments, the reactive particles may each comprise 5-25% aluminum by weight, with the remainder being nickel (e.g. 75-95% nickel). In some embodiments, the reactive particles may each comprise 15-25% aluminum by weight, with the remainder being nickel (e.g. 75-85% nickel). For example, the reactive particles may each comprise approximately 80% nickel and 20% aluminum by weight.

The following are specific, non-exclusive examples of liner composition. In some embodiments, the composition of the liner 10 (e.g. liner powder from which the liner is formed) may include about 2-6% aluminum, about 8-24% nickel, and about 39-80% non-reactive material (such as tungsten, bronze, and/or copper) by weight. In some embodiments, the composition of the liner 10 may include about 3-5% aluminum, about 12-20% nickel, and about 60-80% non-reactive material (such as tungsten, bronze, and/or copper) by weight. In some embodiments, the composition of the liner 10 may include about 4.4% aluminum, about 17.6% nickel, and about 39% tungsten by weight. Some embodiments may have binder material 502 in the liner composition as well, for example with the binder material 502 forming the remaining percentage of the liner 10 (e.g. other than the reactive and non-reactive materials) and/or forming at least about 15% (e.g. 15-20%) by weight of the liner.

Some embodiments may include a shaped charge 20, 30. For example, the shaped charge 20, 30 may include a case 40 having a cavity 50, an explosive load 60 disposed within the cavity 50 of the case 40, and a liner 10 disposed adjacent (e.g. over or in a covering relationship with) the explosive load 60 and configured for retaining the explosive load 60 within the cavity 50 of the case 40. For example, the explosive load 60 may be disposed between the closed end 24 of the case 40 and the liner 10. In some embodiments, the liner 10 may be similar to those embodiments described herein. For example, the liner 10 may include a plurality of non-reactive particles 406 (e.g. configured to not produce a primary exothermic reaction upon detonation) and a plurality of reactive particles 404 (e.g. configured to produce a primary exothermic reaction upon detonation of the shaped charge). The primary reaction may be the most energetic exothermic and/or intermetallic reaction that occurs in the liner 10 upon detonation of the explosive load 60, and may occur between reactants in the reactive particles 404.

FIGS. 2-3 , illustrate the shaped charges 20, 30 including a case 40 defining a cavity 50. According to an aspect, the shaped charges 20, 30 include an explosive load 60 disposed within the cavity 50 of the case 40. A shaped charge liner 10 may be disposed adjacent the explosive load 60, thus retaining the explosive load 60 within the cavity 50 of the case 40. The liner 10A, while shown in a conical configuration in the shaped charges of FIGS. 2-3 , may also be present in a hemispherical configuration 10B as shown in FIG. 1B. The liner 10 may include a composition that includes metal powders. Therefore, the shaped charge liners 10 of the present disclosure may serve multiple purposes, such as, to maintain the explosive load 60 in place until detonation, and to accentuate the explosive effect on the surrounding geological formation (e.g. by exothermic reaction and/or intermetallic reaction).

For purposes of convenience, and not limitation, the general characteristics of the shaped charge liner 10 are described above with respect to the FIG. 1 , and are not repeated hereinbelow. According to an aspect, the liner 10 of the shaped charges 20, 30 includes the composition subtantially as described hereinabove.

The composition of the liner 10 (e.g. the mixture of reactive materials in the reactive particles) may undergo an exothermic reaction, which may occur even at lower energies, such as in shaped charges 20, 30 including when a small or decreased amount of explosive materials, or lower energy explosive materials, is used in the explosive load 60. As illustrated in FIG. 2 , and according to an aspect, the explosive load 60 utilized in the shaped charges 20, 30 may include a primary explosive load 62 and a secondary explosive load 64. The primary explosive load 62 may be positioned between the secondary explosive load 64 and the back wall 46′ of the shaped charge 20, adjacent an initiation point 49 arranged at the back wall 46′. While FIGS. 2 and 3 each illustrate a single initiation point 49, it is envisioned that two of more initiation points 49 may be provided in the shaped charge 20, 30. Alternatively, as illustrated in FIG. 3 , the explosive load 60 may only encompass one layer. A detonating cord 70 (optionally aligned by guiding members 80), may be adjacent the initiation point. While not illustrated in the conical shaped charge 30 of FIG. 3 , it is contemplated that such conical shaped charges may also include primary and secondary explosive loads 62, 64, as the application may require.

Embodiments of the liners 10 of the present disclosure may be used in a variety of shaped charges 20, 30 (e.g. different shapes), which incorporate the described shaped charge liners 10. As noted, the shaped charge of FIG. 2 is a slot shaped charge 20, having an open end 22, and a closed end 24 formed in its flat back wall 46′. In contrast, the shaped charge of FIG. 3 is a conical shaped charge having an open end 22, and a conical shaped back wall 46″. The shaped charges are detonated via a detonation cord 70 that is adjacent an area of the back walls 46′, 46″ and is in communication with an explosive load positioned within a cavity (hollow interior) of the shaped charge.

Method embodiments are also disclosed herein. For example, methods of manufacturing a liner, e.g. for a shaped charge, may include the steps of providing and/or forming reactive particles and providing and/or forming non-reactive particles. According to an aspect, the reactive particles may be formed by at least one of a grinding, a crushing, an agglomeration, water atomization, mechanically cladding, chemical cladding, and a gas atomization process. The forming process for reactive particle may create a conglomerate of two reactive materials, for example, or alternatively a core of a first reactive material coated with a second reactive material (e.g. without a core of non-reactive material or without any substantial amount of non-reactive material). The method further includes mixing/blending the reactive and non-reactive particles to form a liner powder; and forming the liner powder into the liner for the shaped charge. The reactive particles, each having two reactive materials, would be formed before mixing with the non-reactive particles/material. In some embodiments, forming the liner powder into the liner may include compressing the liner powder; and shaping the liner powder into the liner configured to fit within a case for the shaped charge. In some embodiments, shaping the liner powder may include disposing the liner powder within a mold, and/or compressing the liner powder may include compressing the liner powder within the mold.

As described above, the reactive particles may each include two reactive materials which are capable of together undergoing an exothermic and/or intermetallic reaction. In some embodiments, the reactive particles may not include any non-reactive material. In some embodiments, forming the reactive particles may include providing two reactive materials, and forming reactive particles each having both of the reactive materials. In some embodiments, forming the reactive particles may include forming a conglomerate of (e.g. conglomerating) two reactive materials for each reactive particle. In some embodiments, providing the reactive particles may include providing particles which each are a conglomerate of two reactive materials. In some embodiments, each conglomerate particle is formed so that each of the two reactive materials are concentrated at distinct portions of the conglomerate reactive particle. In other embodiments, each of the conglomerate particles may have the two reactive materials distributed throughout, and forming the conglomerate may include mixing the two reactive materials (e.g. approximately homogeneously).

In other embodiments, forming the reactive particles may include forming a core of a first of the two reactive materials, and coating the core with a second of the two reactive materials. In some embodiments, providing the reactive particles may include providing reactive particles having a core of a first of two reactive materials, and a coating of a second of two reactive materials. In some embodiments, the coating encapsulates the core sufficiently to substantially prevent oxidation/exposure to air of the core. In some embodiments, the second reactive material may have lower oxidation properties than the first reactive material. For example, method embodiments may further include selecting the second reactive material of the coating to have low oxidation properties when exposed to air and/or selecting the first reactive material for the core, which oxidizes when exposed to air. In some embodiments, coating the core may include mechanically cladding the core with the coating, chemical cladding the core with the coating, gas atomizing the second of the reactive materials to coat the core of the first reactive material, or plasma spraying the second of the two reactive materials onto the core of the first reactive material. In some embodiments, the reactive particles may be substantially free of non-reactive material. In some embodiments, the reactive materials may include aluminum and nickel. For example, each reactive particle may include approximately 80% nickel and 20% aluminum. In some embodiments, the reactive particles may further include inert material, and forming the reactive particles may include combining the two reactive materials with the inert material.

In some embodiments, the non-reactive particles may only include non-reactive material. In some embodiments, substantially all of the non-reactive material of the liner may be disposed in the non-reactive particles. For example, there may be complete segregation of reactive materials and non-reactive material, with no particles in the composition of the liner having both reactive and non-reactive material. In some embodiments, mixing the reactive and non-reactive particles may include mixing the reactive and non-reactive particles so that the liner powder is homogeneous. In some embodiments, mixing the reactive and non-reactive particles may include mixing about 39-80% non-reactive particles by weight (e.g. approximately 60-80% non-reactive particles) with about 10-30% reactive particles by weight (for example to form the liner blend/powder). In some embodiments, mixing the reactive and non-reactive particles may also include mixing the reactive and non-reactive particles with binder material (which may be in the form of binder particles). In some embodiments, mixing the reactive and non-reactive particles with binder material may include mixing about 39-60% non-reactive particles with about 15-25% reactive particles by weight and with at least about 15% binder material (e.g. 15-20% binder material) by weight.

In some embodiments, forming the liner may include compressing the liner powder under a specified force, such as a force of about of up to about 1,000 kilonewtons (kN) to form the desired liner shape. During the forming step, the liner powder may also be subjected to one or more of a vibrational and a rotational force. The method may, optionally, include sintering the liner powder to form a pressed metallic shaped geometry and forming the pressed metallic shaped geometry into the desired liner shape. The shaped charge liner described herein may, optionally, be formed by a molding process, whereby the composition of metal powders are combined with a binder and placed into an injection mold having a negative imprint of the desired shape of the liner.

Some disclosed method embodiments relate to forming a shaped charge. For example, a shaped charge may be formed having a liner/shaped charge liner utilizing the steps described herein (e.g. providing a liner). The method of forming the shaped charge may include forming a case having a side wall, a back wall, a hollow interior (e.g. cavity) defined by the side wall and the back wall, and an initiation point positioned adjacent to (or within) the back wall. The method may further include disposing an explosive load within the hollow interior of the case, so that the explosive load is adjacent the back wall, the initiation point, and at least a portion of the side wall. According to an aspect, the explosive load includes one or more explosive powders that are arranged within the hollow interior. The explosive powders may be loosely place in the hollow interior/cavity. In an embodiment, the explosive load may be compressed within the hollow interior/cavity of the case at a force of between about 20 kN to about 1,000 kN. In an alternative embodiment, the explosive load may be compressed at a force of between about 30 kN to about 600 kN. The method may further include installing the shaped charge liner adjacent (e.g. disposed over) the explosive load and compressing it into the explosive load, such that the explosive load is positioned between the back and side walls, and the shaped charge liner.

Forming the liner out of separate reactive and non-reactive particles may yield more efficient exothermic and/or intermetallic reactions. For example, by having separate reactive and non-reactive particles, the reactive materials in the reactive particles may react together first and/or be more prone to react together (e.g. due to proximity and/or intimate contact), so that the effectiveness of the reactive materials is not “consumed” or wasted by less effective reactions (e.g. secondary reactions with non-reactive materials). Testing has illustrated exemplary benefits which may arise from some disclosed embodiments. For example, based on six identical API 19B Section IV test shots on Berea rock, comparing identical shaped charges with standard DynaEnergetics DPEX reactive liner to exemplary disclosed liner having 22% by weight Aluminum-Nickel reactive particles (each having 80% Nickel and 20% Aluminum), 39% by weight non-reactive particles (e.g. tungsten), and the remainder by weight percentage binder material (e.g. lead), the following results may be observed: a 7% increase in clean tunnel for the exemplary disclosed liner compared to standard DPEX, 13% more tunnel volume for the exemplary disclosed liner compared to standard DPEX, and 21% more production ratio for the exemplary disclosed liner compared to standard DPEX. For example, the exemplary disclosed liner shaped charges may result in 99% clean tunnel. In some embodiments, the exemplary disclosed liner shaped charges may result in 5% larger entry hole diameter. These listed test results are merely exemplary, and are not intended to limit the scope of this disclosure.

The components of the apparatus illustrated are not limited to the specific embodiments described herein, but rather, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the apparatus include such modifications and variations. Further, steps described in the method may be utilized independently and separately from other steps described herein.

While the apparatus and method have been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope contemplated. In addition, many modifications may be made to adapt a particular situation or material to the teachings found herein without departing from the essential scope thereof.

The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.

In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The terms “a” (or “an”) and “the” refer to one or more of that entity, thereby including plural referents unless the context clearly dictates otherwise. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. Furthermore, references to “one embodiment”, “some embodiments”, “an embodiment” and the like are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” or “approximately” is not to be limited to the precise value specified. Such approximating language may refer to the specific value and/or may include a range of values that may have the same impact or effect as understood by persons of ordinary skill in the art field. For example, approximating language may include a range of +/−10%, +/−5%, or +/−3%. The term “substantially” as used herein is used in the common way understood by persons of skill in the art field with regard to patents, and may in some instances function as approximating language. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Terms such as “first,” “second,” “upper,” “lower” etc. are used to identify one element from another, and unless otherwise specified are not meant to refer to a particular order or number of elements.

As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while considering that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur—this distinction is captured by the terms “may” and “may be.”

As used in the claims, the word “comprises” and its grammatical variants logically also subtend and include phrases of varying and differing extent such as for example, but not limited thereto, “consisting essentially of” and “consisting of.”

Where necessary, ranges have been supplied, and those ranges are inclusive of all sub-ranges therebetween. It is to be expected that variations in these ranges will suggest themselves to a practitioner having ordinary skill in the art and, where not already dedicated to the public, the appended claims should cover those variations.

This disclosure is presented for purposes of illustration and description. This disclosure is not limited to the form or forms disclosed herein. In the Detailed Description of this disclosure, for example, various features of some exemplary embodiments are grouped together to representatively describe those and other contemplated embodiments, configurations, and aspects, to the extent that including in this disclosure a description of every potential embodiment, variant, and combination of features is not feasible. Thus, the features of the disclosed embodiments, configurations, and aspects may be combined in alternate embodiments, configurations, and aspects not expressly discussed above. For example, the features recited in the following claims lie in less than all features of a single disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

Advances in science and technology may make equivalents and substitutions possible that are not now contemplated by reason of the imprecision of language; these variations should be covered by the appended claims. This written description uses examples to disclose the devices, compositions, and methods in accordance with the disclosure, and also to enable any person of ordinary skill in the art to practice these, including making and using any compositions, devices incorporating the compositions, and performing any incorporated manufacturing methods. The patentable scope thereof is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. 

What is claimed is:
 1. A liner for a shaped charge, comprising: a plurality of non-reactive particles; and a plurality of reactive particles configured to produce an exothermic reaction upon detonation of the shaped charge, wherein: the reactive particles each comprise two reactive materials which together are capable of undergoing an exothermic or intermetallic reaction; and the reactive particles are substantially free of any non-reactive material.
 2. The liner of claim 1, wherein the non-reactive particles each comprise non-reactive material, and the non-reactive material consists essentially of material that does not react with one or both of the reactive materials in a primary exothermic or intermetallic reaction.
 3. The liner of claim 2, wherein the non-reactive material is denser than the reactive materials.
 4. The liner of claim 1, wherein the non-reactive particles consist essentially of non-reactive material.
 5. The liner of claim 2, wherein substantially all of the non-reactive material of the liner is disposed in the non-reactive particles.
 6. The liner of claim 1, wherein the reactive particles consist essentially of the two reactive materials.
 7. The liner of claim 2, wherein the reactive particles further comprise an inert material; wherein the inert material of the reactive particles is capable of reacting with the rock formation, but is not capable of interacting in a primary exothermic or intermetallic reaction with one or both of the reactive materials of the reactive particles; and wherein the inert material is less dense than the non-reactive material.
 8. The liner of claim 1, wherein the reactive particles each comprise a conglomerate of the two reactive materials.
 9. The liner of claim 1, wherein the reactive particles each comprise a core of a first of the two reactive materials, which is coated with a second of the two reactive materials.
 10. A method of manufacturing a liner for a shaped charge, comprising the steps of: providing reactive particles, the reactive particles each including two reactive materials; providing non-reactive particles; mixing the reactive particles and non-reactive particles to form a liner powder; compressing the liner powder; and shaping the liner powder into the liner configured to fit within a case for the shaped charge; wherein: the two reactive materials together are capable of undergoing an exothermic or intermetallic reaction; and the reactive particles are substantially free of any non-reactive material.
 11. The method of claim 10, wherein the non-reactive material consists essentially of material that does not react with one or both of the reactive materials in a primary exothermic or intermetallic reaction.
 12. The method of claim 10, wherein the reactive particles each comprise a conglomerate of the two reactive materials, and wherein forming the reactive particles comprises forming the two reactive materials into conglomerate particles.
 13. The method of claim 10, wherein the reactive particles each comprise a core of a first of the two reactive materials, which is coated with a second of the two reactive materials; and wherein forming the reactive particles comprises providing the core of the first of the two reactive materials, and coating the core with the second of the two reactive materials.
 14. The method of claim 10, further comprising providing a binder material, wherein mixing the reactive particles and non-reactive particles to form a liner powder further comprises mixing the reactive particles, the non-reactive particles, and the binder material to form the liner powder.
 15. A liner for a shaped charge, comprising: a plurality of non-reactive particles each comprising non-reactive material; and a plurality of reactive particles configured to produce an exothermic intermetallic reaction upon detonation of the shaped charge, wherein: the reactive particles each comprise aluminum and nickel; and the reactive particles each comprise: a conglomerate of the aluminum and nickel, or a core of a first one of the aluminum and nickel, which is coated with a second one of the aluminum and nickel.
 16. The liner of claim 15, wherein the reactive particles each comprise the core of aluminum coated with a coating of nickel.
 17. The liner of claim 15, wherein the reactive particles are substantially free of non-reactive material.
 18. The liner of claim 15, wherein the non-reactive particles consist essentially of non-reactive material.
 19. The liner of claim 15, wherein substantially all of the non-reactive material of the liner is disposed in the non-reactive particles.
 20. The liner of claim 15, wherein the reactive particles each further comprise chromium. 